MySQL Forums
Forum List  »  InnoDB

How to improve sort speed for large single queries?
Posted by: Bob Bankay
Date: February 09, 2005 09:24PM

We have some very large statistics query that run against a mid sized table, about 10M rows and 10GB size.

The query is complex with many stepped phases that use 'ordered' and 'grouped'. The last time I ran the query it took about 2800 sec. The first 400 sec it did a lot of innodb IOs, and the rest of the time iostat showed lots of IO activity so I assumed that it was sorting. Here are some values that we have for per-thread buffers (I believe):

set-variable = sort_buffer=6M
set-variable = record_buffer=4M

This is fairly large compare to cnf examples that I have seen. Does it help large query performance? I there anything else that would?

Options: ReplyQuote

Written By
How to improve sort speed for large single queries?
February 09, 2005 09:24PM

Sorry, you can't reply to this topic. It has been closed.

Content reproduced on this site is the property of the respective copyright holders. It is not reviewed in advance by Oracle and does not necessarily represent the opinion of Oracle or any other party.